1. Field of the Invention
The present invention relates to an image sensing apparatus for suppressing bounds of, for example, a quick return mirror of an image sensing apparatus.
2. Description of the Related Arts
Conventionally, in a quick return mirror mechanism of, for example, a single-lens reflex camera, a main mirror and sub-mirror are rotated at high speed to positions inside and outside an optical path (photographing optical path) from a photographing optical system. In the photographing optical path, the mirrors are aligned at predetermined stop positions when they contact against stoppers arranged in a mirror box, and guide light to a viewfinder optical system and focus detection unit.
In the quick return mirror mechanism, a phenomenon in which the mirrors bound since they collide against the stoppers when the mirrors are rotated at high speed from the position outside the photographing optical path to the position inside the photographing optical path (to be referred to as a return timing hereinafter) occurs (to be referred to as a mirror bound phenomenon hereinafter). By shortening a time required to stop the mirror bound phenomenon (to be referred to as a bound suppression time), a focus detection operation can be started earlier, and a larger number of photographs per unit times can be taken in a continuous shooting mode.
For example, Japanese Patent Laid-Open No. 7-036105 describes a technique which decides a moment of inertia of a mirror support member and/or a mirror member so that a bound time in which each mirror collides against the mirror support member and bounds is shorter than the bound suppression time when the mirror support member is secured.
However, in Japanese Patent Laid-Open No. 7-036105, a stop position of the mirror support member changes when each mirror is aligned and adjusted. As a result of this change, since a movable range of a rotation alignment member changes, an impact absorption effect changes, thus causing bound suppression time variations.